The present invention relates to a blind rivet setting tool and, more specifically, to a blind rivet setting tool that does not allow a riveting operation to be performed unless a blind rivet is properly pressed against a workpiece.
A conventional blind rivet comprises a rivet body and a mandrel and is made of a metal such as aluminum or steel, for example. The rivet body has a hollow sleeve with a flange at one end of the sleeve. The mandrel has a head abutting an opposite end of the sleeve and a shank that extends from the head through the sleeve and projects beyond the flange. A blind rivet has the advantage of being able to be fastened to a workpiece, such as a panel, from one side.
Blind rivets are fastened to workpieces using a blind rivet setting tool. One type of conventional blind rivet setting tool has a jaw in a nose at the tip of the tool to grip the shank of a blind rivet mandrel that is inserted into the nose. After the rivet body protruding from the nose is inserted into a mounting hole in a workpiece, such as a panel, until the flange abuts one side of the workpiece, a trigger on the setting tool is squeezed to actuate a piston pneumatically. The piston has a rod that moves in a hydraulic cylinder to generate hydraulic pressure that pulls the jaw inwardly of the tool. As the head of the mandrel is pulled toward the flange, the sleeve of the rivet body expands, and then the shank of the mandrel breaks off. The expanded portion of the sleeve and the flange embrace the workpiece and fasten the rivet body to the workpiece.
One such blind rivet setting tool has a main body that extends rearwardly from the nose, and has a handle associated with the trigger that extends perpendicularly from the main body to be held by an operator when the tool is in use. When an operator grips the handle and holds the tool over a workpiece at a level above the operator's hips, the gripping hand of the operator is in an unnatural position, making it difficult to hold and operate the tool.
An example of a tool constructed to address this problem is disclosed in Kokai 2002-018544 (Patent Document 1). This tool comprises a nose, a housing extending rearwardly from the nose, and a pneumatic cylinder extending rearwardly from the housing. A hydraulic piston-cylinder device is positioned near the pneumatic cylinder inside the housing. The tool extends straight back from the nose to the pneumatic cylinder. A handle to be gripped by an operator is formed on a housing portion of the tool, and a trigger lever is attached to a portion of the handle. To use the tool to fasten a blind rivet to a workpiece from above the workpiece, the operator grips the handle, and lowers the nose of the tool. When the trigger on the handle is squeezed, compressed air from a supply pipe enters the pneumatic cylinder, hydraulic fluid enters the hydraulic piston-cylinder device, and the rivet is fastened to the workplace.
However, in the blind rivet setting tool described in Patent Document 1, the trigger can be operated even when the flange on the rivet body is not properly pressed against a workpiece, and defective fastening of the rivet body to the workpiece may occur if space remains between the flange and the workpiece.
A blind rivet setting tool disclosed in Kokai 2000-351042 (Patent Document 2) prevents a mandrel from being pulled by the tool when the flange on the rivet body is not pressed against a workpiece, but this tool does not have the advantage of the tool in Patent Document 1, because the handle with the attached trigger is perpendicular to the main body of the tool.